2nd/10_Wiki/Topics/Frontend/Server Side Rendering (SSR).md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-server-side-rendering-ssr	Server Side Rendering (SSR)	10_Wiki/Topics	verified	self	SSR Server Rendering isomorphic rendering	none	A	0.95	applied	ssr react nextjs rendering performance		2026-05-10	pending	language framework TypeScript Next.js 15 / React 19

Server Side Rendering (SSR)

매 한 줄

"매 SSR 은 server 에서 HTML 을 생성해 first paint 를 빠르게, SEO 를 가능하게". 2026 기준 React 19 의 streaming SSR + Suspense + Server Components 가 표준. 매 trade-off 는 server compute cost vs CSR-only 의 blank-screen 제거. 매 modern 변형: SSG (build-time), ISR (revalidate), PPR (Partial Prerender).

매 핵심

매 rendering modes

• CSR: 매 client only — slow first paint, no SEO without JS
• SSR: 매 server-render full HTML per request
• SSG: 매 build-time HTML (static)
• ISR: 매 SSG + on-demand or time-based revalidation
• PPR: 매 partial prerender — static shell + dynamic holes (Next.js 15)

매 hydration

• Server HTML 송신 → client JS 가 attach (event handler 연결)
• Streaming SSR: HTML 을 chunk 로 진행 송신
• Selective hydration: visible / interacted 부분 우선

매 응용

1. Marketing / blog (SEO + fast paint).
2. E-commerce PDP (per-user pricing + SEO).
3. Dashboard shells (PPR — static shell + dynamic data).

💻 패턴

Next.js 15 RSC + streaming

// app/page.tsx
import { Suspense } from "react";
import { ProductGrid } from "./product-grid";

export default function Page() {
  return (
    <main>
      <h1>Products</h1>
      <Suspense fallback={<div>매 loading…</div>}>
        <ProductGrid />
      </Suspense>
    </main>
  );
}

// app/product-grid.tsx (RSC, runs on server)
import { db } from "@/lib/db";

export async function ProductGrid() {
  const products = await db.product.findMany({ take: 20 });
  return (
    <ul>
      {products.map((p) => <li key={p.id}>{p.name}</li>)}
    </ul>
  );
}

Partial Prerendering (PPR)

// app/dashboard/page.tsx
export const experimental_ppr = true;

import { Suspense } from "react";
import { StaticHeader } from "./header";
import { LiveMetrics } from "./metrics";

export default function Page() {
  return (
    <>
      <StaticHeader />  {/* prerendered */}
      <Suspense fallback={<MetricsSkeleton />}>
        <LiveMetrics />  {/* dynamic, streamed */}
      </Suspense>
    </>
  );
}

ISR with revalidate

// app/posts/[slug]/page.tsx
export const revalidate = 60;  // every 60s

export default async function Page({
  params,
}: { params: Promise<{ slug: string }> }) {
  const { slug } = await params;
  const post = await fetch(`https://api.example.com/posts/${slug}`,
    { next: { revalidate: 60, tags: [`post:${slug}`] } }).then((r) => r.json());
  return <article>{post.title}</article>;
}

On-demand revalidation

// app/api/revalidate/route.ts
import { revalidateTag } from "next/cache";

export async function POST(req: Request) {
  const { tag } = await req.json();
  revalidateTag(tag);
  return Response.json({ ok: true });
}

Pure React 19 streaming SSR

// server.ts
import { renderToReadableStream } from "react-dom/server";
import App from "./App";

export default async function handler(req: Request): Promise<Response> {
  const stream = await renderToReadableStream(<App url={req.url} />, {
    bootstrapModules: ["/client.js"],
    onError: (err) => console.error(err),
  });
  await stream.allReady;  // remove for true streaming
  return new Response(stream, {
    headers: { "content-type": "text/html" },
  });
}

Client hydration entry

// client.ts
import { hydrateRoot } from "react-dom/client";
import App from "./App";

hydrateRoot(document, <App url={location.href} />);

Cache headers for SSR

// app/api/data/route.ts
export async function GET() {
  return Response.json(
    { data: 42 },
    {
      headers: {
        "Cache-Control": "public, s-maxage=60, stale-while-revalidate=300",
      },
    },
  );
}

Server-only utility

// lib/server-only.ts
import "server-only";  // 매 import in client component throws

import { db } from "./db";

export async function loadSecret() {
  return db.secret.findFirst();
}

Edge runtime SSR

// app/page.tsx
export const runtime = "edge";

export default async function Page() {
  const data = await fetch("https://api.example.com/edge").then((r) => r.json());
  return <pre>{JSON.stringify(data)}</pre>;
}

매 결정 기준

상황	Approach
Static marketing page	SSG (generateStaticParams)
Per-user dynamic	SSR / RSC
Mostly static + small dynamic	PPR
Data refreshes minutes-scale	ISR with revalidate
Internal app, no SEO	CSR (Vite SPA) sufficient
Low latency global	Edge runtime SSR

기본값: Next.js 15 App Router + RSC + Suspense streaming + PPR where applicable.

🔗 Graph

• 부모: Rendering Strategies · Web Performance
• 변형: CSR · SSG · ISR · Streaming SSR
• 응용: Remix · SvelteKit · Nuxt
• Adjacent: React Server Components — 경계 의식 · Hydration · Suspense

🤖 LLM 활용

언제: rendering strategy 결정, SEO + first paint 최적화, RSC + Suspense 설계. 언제 X: 매 internal admin tool with auth-only access (CSR 충분), 매 매우 dynamic real-time app (WebSocket-driven).

❌ 안티패턴

• SSR everything: 매 unnecessary server compute. 매 marketing page → SSG.
• No streaming: 매 await all data → blank for 5s. 매 Suspense + streaming.
• Hydration mismatch: server Date.now() vs client → 매 warning. suppressHydrationWarning 또는 client-only render.
• Secret in client component: 매 env var leak. server-only import.
• Massive RSC payload: 매 props 에 huge JSON. 매 boundary 재설계.
• Forgetting cache tags: ISR 인데 invalidation 못 함.

🧪 검증 / 중복

• Verified (Next.js 15 docs, React 19 docs, Vercel blog 2026).
• 신뢰도 A.

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — SSR full content